Lifting devices are commonly used to lift vehicles for servicing and maintenance. Currently hydraulic hoists can be used to produce an 18 inch lift. Hoists pick up the entire car and can lift up to 8 feet. However, hydraulic hoists are expensive and produce a higher than required lift making them inefficient. This is because hoists are meant to pick up the entire car.
Sometimes it is desirable to only lift one axle in the front or back of a vehicle. Jacks are such devices that meant to pick up only one axle of a car (front or back). A hydraulic jack currently on the market has a lifting capacity of 12,000 lbs, and can be slightly modified to lift anywhere from 6,000 lbs to 50,000 lbs. Typically these jacks are not stand-alone jacks and are used as an add-on to hoists. They are generally designed to roll along a rail.